Fuel fitting

ABSTRACT

A fuel inlet fitting for an internal combustion engine carburetor has a depending hollow post with exterior lugs for cooperating with interior lugs depending about an inlet opening in the roof of the float bowl of the carburetor to draw and seal the fitting against the roof. A float valve is translatable in an outlet port through the post and is retained therein by an annular lip. The fitting and float bowl roof have detent means to lock the fitting in a fixed position with respect to the float bowl.

United States Patent [191 Elam 1 1 May 1,1973

[54] FUEL FITTING [75] lnventor: Charles F. Elam, Rochester, NY.

[73] Assignee: General Motors Detroit, Mich.

22 Filed: July 9, 1971 21 App1.No.: 161,130

Corporation,

[52] U.S. Cl. ..261/4, 261/70, 210/232, 210/441 [51] Int. Cl ..F02m 19/06 [58] Field of Search ..261/4, 70; 210/232, 210/441, 454, 459

[56] References Cited UNITED STATES PATENTS Carlson et a1. ..261/70 12/1962 Hultgren et a1 ..210/441 X 5/1967 Stoltman ..261/50 A Primary Examiner-Tim R. Miles Attorney-E. W. Christen et a1.

[57] ABSTRACT A fuel inlet fitting for an internal combustion engine carburetor has a depending hollow post with exterior lugs for cooperating with interior lugs depending about an inlet opening in the roof of the float bowl of the carburetor to draw and seal the fitting against the roof. Afloat valve is translatable in an outlet port through the post and is retained therein by an annular lip. The fitting and float bowl roof have detent means to lock the fitting in a fixed position with respect to the float bowl.

4 Claims, 3 Drawing Figures FUEL FITTING This invention relates to fuel fittings and more particularly to fuel inlet fittings for internal combustion engine carburetors.

The fuel filter of a carburetor may clog and the float valve will wear with extended use so that both therefore require periodic service. The present invention facilitates such service by providing a separately attachable fuel inlet fitting that contains both the float valve and filter and has connecting structure for sealing and locking the fitting to the float bowl roof of the car-- buretor.

The fuel inlet fitting according to the present inven tion has a post that depends about an outlet port in the housing of the fitting. The post extends into the carburetor float bowl and has exterior lugs with cams to cooperate with similar lugs depending from an inlet opening in the float bowl roof for drawing the fitting against the roof. When the lugs draw the fitting against the roof, an oblong protrusion from the housing snaps into a depression in the roof to lock the inlet port of the fitting into a fixed position on the roof and to let an annular sealing rib about the post seal the housing against the roof. A float valve is retained in an outlet port through the post by an internal lip at the bowl end of the post and is translated in the outlet port by a float. The housing has a filter chamber communicating with an inlet port and the outlet port. A filter element that includes a cylindrical screen embedded in an annular cap and in an annular rim is press-fitted and ultrasonically welded into the chamber between the inlet and outlet ports.

It is therefore a primary object of the present invention to provide a new and improved fuel inlet fitting for an internal combustion engine carburetor.

It is another primary object of the present invention to provide, for an internal combustion engine carburetor, a fuel inlet fitting having a post for retaining a translatable float valve and for cooperating with the float bowl of the carburetor to forcingly seat, seal and hold the fitting relative to the float bowl.

It is a further and more specific object of the present invention to provide a fuel inlet fitting of the foregoing type where the carburetor and fitting have detent structure for locking the fitting in a fixed position on the roof of the float bowl.

It is a further and more specific object of the present invention to provide an internal combustion engine carburetor having structure to draw and seal against the float bowl roof thereof a separately attachable fuel inlet fitting containing a filter and a translatable float valve.

These and other features, objects and details of the present invention will become more apparent with reference to the following description taken in conjunction with the following drawings wherein:

FIG. 1 is a cross sectional view of a carburetor having a fuel inlet fitting constructed in accordance with the present invention;

FIG. 2 is an enlarged cross sectional view of the inlet fitting of FIG. 1; and,

FIG. 3 is an isometric, exploded view of the attaching structure of FIG. I.

With reference now to FIG. 1, there is shown a carburetor 10 comprising a body 12 and an air horn 14 that are joined to provide a mixing conduit 16 and a closed float bowl 18, the latter having a fuel inlet fitting 20. A manually operable throttle valve 22 is pivotally disposed in body 12 and an air valve 24 is pivotally disposed in air horn 14 on a shaft 26. Also pivotally disposed in air horn 14 is a choke valve 28 controlled in a conventional manner by a thermostatic member (not shown) and a vacuum brake mechanism 30. Vacuum brake mechanism 30 includes a diaphragm 32 communicating on its lefthand side with the vacuum on the downstream side of throttle valve 22 via vacuum conduits 34a and 34b. Before the engine to which carburetor 10 is attached is started, choke valve 28 is closed by the thermostatic element. However, as soon as the engine begins to run under its own power, diaphragm 32 is pulled to the left and a plunger 36 secured thereto pulls choke valve 28 to a slightly open position to lean the mixture.

Rotated with air valve 24 and pinned thereto by pin 21 is a rod carrier 23 carrying a tapered metering rod '25 extending through a metering orifice 27 communicating with float bowl 18 through a fuel passage 29. Shaft 26 is connected by links (not shown) to a spring (not shown) that cooperates with upstream and downstream pressures on air valve 24 to position the air valve to maintain a constant pressure differential thereacross. A flow of fuel through orifice 27 is controlled in accordance with a flow of air past air valve 24 by the displacement of rod 25 to vary the area through orifice 27. Increasing fuel flow is effected for increasing opening of air valve 24 by leftward or clockwise displacement of rod 25 in orifice 27. To adjust the flow of fuel in accordance with the flow of air to effect a desired air-fuel mixture, an adjusting screw 31 is provided to adjust the radial position of rod carrier 23 relative to air valve 24, thereby accurately determining the position of rod 25 in orifice 27 Float bowl 18 includes wall 50 integral with body 12 and a roof 52 integral with air horn 14. A float 54 is pivotally disposed from wall 50 by a hinge 56, the movable portion of which is located opposite a hub 58 depending into float bowl 18 from roof 52 and having an inlet opening or conduit 60 therethrough. Except for fitting 20 and the attaching structure described below, carburetor 10 is shown and described in greater detail in US. Pat. No. 3,322,408 issued to Donald D. Stoltman, and assigned to the assignee of the present invention.

Fuel inlet fitting 20 according to the present invention comprises a housing or body having a fuel inlet means 71, fuel outlet means 72 at right angles thereto, fuel filter chamber means 74 communicating with inlet and outlet means 71 and 72 and having fuel filter means 76 inserted therebetween, and attachment and valve retaining means 78 depending from a base 80 about outlet means 72.

With reference to the enlarged details shown in FIG. 3, attachment and valve retaining means 78 comprises a post 82 having four lugs or projections 84 spaced circumferentially and equally thereabout, each lug having at its upper end a cam or pitched surface 86 facing toward base 80. To lock fitting 20 against axial movement relative to float bowl roof 52, lugs 84 cooperate with four lugs or porjections 66 spaced equally and circumferentially about float bowl inlet 60, each lug 66 terminating in a cam or pitch surface 68 facing float bowl 18 for engaging a cam surface 86 of a lug 84. To prevent leakage of fuel from fuel bowl 18 betwwen opening 60 and post 82, base 80 has a protruding annular sealing rim 90 about the post 82 that is urged against a continuous surface 62 of roof 52 about inlet opening 60 by the camming action of cams 68 and 86.

To attach fuel inlet fitting to float bowl roof 52, post 82 is first inserted into inlet opening 60 of float bowl hub 58 so that external lugs 84 on post 82 pass between internal lugs 66 on hub 58. Fitting 20 is then given a one-eighth turn or 45 so that cams 86 of external lugs 84 cooperate with cam 68 of hub 58 to forcingly seat fitting 20 against roof 52. Roof 52 and base 80 have cooperating detent means 87 here in the form of an external oblong projection 88 from base 80 that snaps into a depression 89 on roof 52 during the turning of fitting 20 after indexing lugs 84 into proper position with respect to lugs 66. These detent means therefore cooperate to align lugs 84 axially with lugs 66 while also preventing the circumferential force effected by cams 68 and 86 from unscrewing the fitting 20 and also locking inlet means into a predetermined position on roof 52 for alignment with a subsequently connected fuel conduit 91.

Fuel outlet means 72 comprises an outlet port 92 extending through floor 80 and post 82 and terminated at one end by an inwardly extending lip 94, a recess 96 communicating with the other end of outlet port 92 and terminating in an inwardly extending lip 98, a valve seat 99 here metallic with an opening therethrough communicating with outlet port 92 and retained in recess 96 by lip 98, and a float valve 100 here also metallic translatable in outlet port 92 and having integral arms or flutes 102 retained in outlet port 92 upon engagement with lip 94. Float valve 100 has a float end 104 protruding beyond lip 94 of outlet port 92 between a wide open position when arms 102 are engaged by lip 94 and a closed position when head 106 of float valve 100 is seated in seat 99. With fitting 20 attached to float bowl l8, float end 104 of float valve 100 is in contact with and moved up and down by hinge 56 of float 54 as float 54 follows the level of fuel (not shown) in fuel bowl 18.

Sufficient radial clearance is provided between the exterior of float arm 102 and outlet port 92 to allow translation of float valve 100 therein. Should fitting 20 be removed for servicing, float valve 100 would be removed therewith due to the retaining cooperation between float valve arms 102 and outlet port lip 94.

Filter chamber 74 has an axially extending wall 100 spaced between a top groove 1 l2 counterbored therein and a bottom shoulder 114 located adjacent base 80 about outlet opening 92. Inserted to close the top of chamber means 74 is filter means 76 that includes a cap 116 located against and ultrasonically sealed in groove.-

Filter means 76 divides filter chamber 74 into an inlet chamber 124 and an outlet chamber 126. Inlet chamber 124 is defined by the generally cylindrical space about the exterior of screen 122 between cap 116 and rim 120 and communicates with an inlet port 128 spaced intermediate groove 112 and shoulder 114. Outlet chamber 126 comprises the space within screen 122 between cap 116 and base 80 and, as shown in FIG. 2, communicates with outlet means 72 while completely surrounding recess 96 and seat retaing lip 98 thereof.

With a fuel supply conduit 91 connected to inlet means and with the fuel in float bowl 18 below a predetermined level, float 54 drops so that hinge 56 allows valve 102 to be unseated both by gravity and by fuel flowing through inlet port 128 and valve seat 99. It has been found that dirt that might be collected on screen-122 when fuel flows from inlet chamber 124 to outlet chamber 128 falls to and is collected at the annular bottom of inlet chamber 124 when the, flow is stopped, thereby providing a self-cleaning feature that enhances the life of not only screen 122 but also that of the entire inlet fitting.

Having described one embodiment of the present invention it is understood that the specific terms and examples are employed in a descriptive sense only andnot for the purpose of limitation. Other embodiments of the invention, modifications thereof, and alternatives thereto may be used. I therefore aim in the appended claims to cover such modifications and changes as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A fuel inlet fitting for attaching a fuel line to a float bowl of an internal combusion carburetor comprising:

a. a housing having a chamber, a fuel inlet port communicating with said chamber, a fuel outlet port communicating with said chamber, and annular sealing means about said outlet port;

. fuel filter means inserted in said chamber between said ports; and,

c. post means depending from said housing about said outlet for extending into said float bowl and 4 for attaching said fitting to said float bowl, said post means having a plurality of lugs spaced circumferentially thereabout, each lug having a cam surface for cooperating with said float bowl to forcingly seat and seal said fitting against said float bowl.

2. A fuel inlet fitting for attaching a fuel line to a float bowl of an internal combustion engine carburetor comprising:

a. a housing having a chamber, a fuel inlet port communicating with said chamber, and a fuel outlet port communicating with said chamber;

b. fuel filter means inserted in said chamber and sealed between said ports;

post means depending from said housing about said outlet port for extending into said float bowl and for attaching said fitting to said float bowl, said post means having a lip extending into said outlet port and a plurality of lugs, said lugs spaced circumferentially about said port, each said lug having a cam surface for cooperating with said float bowl to forcingly seat said fitting relative to said float bowl; and

float valve means translatable in said outlet port and retained therein by said lip on said post, whereby said float valve means are removable from said float bowl with said fitting.

An internal combustion engine carburetor comprising:

the carburetor float bowl having a roof and a float pivoted with respect to said roof, said roof having an inlet opening therethrough and a plurality of lugs spaced equally and circumferentially about said opening, each said lug having a cam surface facing from said roof;

. a housing having a chamber, an inlet port communicating with said chamber, and an outlet port communicating with said chamber;

. fuel filter means inserted in said chamber between said ports;

. post means integral with said housing and depend said housing in a fixed position on said float bowl roof; and,

g. a plurality of seating lugs on said post means spaced equally and circumferentially thereabout, each said lug having a cam surface facing said housing for cooperating with said cam surfaces on said float bowl to draw said housing against said float bowl roof while said locking means lock therebetween.

4. An internal combustion engine carburetor comprising:

a. a carburetor float bowl having a roof and a float pivoted with respect to said roof, said roof having an inlet opening therethrough above said float bowl and having a plurality of lugs spaced equally and circumferentially about said opening, each said lug having a cam surface facing from said roof;

b. a housing having a chamber, an inlet port communicating with said chamber, and an outlet port communicating with said chamber;

c. fuel filter means inserted and sealed between said inlet and outlet ports;

d. post means integral with said housing and extending axially about said outlet port;

e. lip means at a float bowl end of said post extending into said outlet port;

f. recess means about said outlet port at the other end of said post;

g. valve seat means having an opening therethrough retained in said recess means;

h. float valve means translatable in said outlet port between said seat means and said lip, said float valve means having a float end extending from said post past said lip into said float bowl for cooperating with said float to translate said float valve between said recess and said lip;

. annular sealing means on said housing about said post and on said roof about said inlet opening for sealing said housing to said float bowl roof;

j. locking means on said housing and roof for locking said housing into a fixed position on said float bowl roof; and, i

. a plurality of lugs on said post spaced equally and circumferentially thereabout, each said lug having a cam surface facing said housing for cooperating with said cam surfaces on said float bowl lugs to draw said housing against said float bowl roof while said seal means seal therebetween and said locking means lock therebetween. 

1. A fuel inlet fitting for attaching a fuel line to a float bowl of an internal combusion carburetor comprising: a. a housing having a chamber, a fuel inlet port communicating with said chamber, a fuel outlet port communicating with said chamber, and annular sealing means about said outlet port; b. fuel filter means inserted in said chamber between said ports; and, c. post means depending from said housing about said outlet for extending into said float bowl and for attaching said fitting to said float bowl, said post means having a plurality of lugs spaced circumferentially thereabout, each lug having a cam surface for cooperating with said float bowl to forcingly seat and seal said fitting against said float bowl.
 2. A fuel inlet fitting for attaching a fuel line to a float bowl of an internal combustion engine carburetor comprising: a. a housing having a chamber, a fuel inlet port communicating with said chamber, and a fuel outlet port communicating with said chamber; b. fuel filter means inserted in said chamber and sealed between said ports; c. post means depending from said housing about said outlet port for extending into said float bowl and for attaching said fitting to said float bowl, said post means having a lip extending into said outlet port and a plurality of lugs, said lugs spaced circumferentially about said port, each said lug having a cam surface for cooperating with said float bowl to forcingly seat said fitting relative to said float bowl; and d. float valve means translatable in said outlet port and retained therein by said lip on said post, whereby said float valve means are removable from said float bowl with said fitting.
 3. An internal combustion engine carburetor comprising: a. the carburetor float bowl having a roof and a float pivoted with respect to said roof, said roof having an inlet opening therethrough and a plurality of lugs spaced equally and circumferentially about said opening, each said lug having a cam surface facing from said roof; b. a housing having a chamber, an inlet port communicating with said chamber, and an outlet port communicating with said chamber; c. fuel filter means inserted in said chamber between said ports; d. post means integral with said housing and depending therefrom about said outlet port for extending into said float bowl and for attaching said housing to said float bowl, said post means having at a float bowl end thereof a lip extending into said outlet port; e. float valve means translatable in said outlet port and retained therein by said lip; f. locking means on said housing and roof for locking said housing in a fixed position on said float bowl roof; and, g. a plurality of seating lugs on said post means spaced equally and circumferentially thereabout, each said lug having a cam surface facing said housing for cooperating with said cam surfaces on said float bowl to draw said housing against said float bowl roof while said locking means lock therebetween.
 4. An internal combustion engine carburetor comprising: a. a carburetor float bowl having a roof and a float pivoted with respect to said roof, said roof having an inlet opening therethrough above said float bowl and having a plurality of lugs spaced equally aNd circumferentially about said opening, each said lug having a cam surface facing from said roof; b. a housing having a chamber, an inlet port communicating with said chamber, and an outlet port communicating with said chamber; c. fuel filter means inserted and sealed between said inlet and outlet ports; d. post means integral with said housing and extending axially about said outlet port; e. lip means at a float bowl end of said post extending into said outlet port; f. recess means about said outlet port at the other end of said post; g. valve seat means having an opening therethrough retained in said recess means; h. float valve means translatable in said outlet port between said seat means and said lip, said float valve means having a float end extending from said post past said lip into said float bowl for cooperating with said float to translate said float valve between said recess and said lip; i. annular sealing means on said housing about said post and on said roof about said inlet opening for sealing said housing to said float bowl roof; j. locking means on said housing and roof for locking said housing into a fixed position on said float bowl roof; and, k. a plurality of lugs on said post spaced equally and circumferentially thereabout, each said lug having a cam surface facing said housing for cooperating with said cam surfaces on said float bowl lugs to draw said housing against said float bowl roof while said seal means seal therebetween and said locking means lock therebetween. 